unregister_blkdev(): return void

Put WARN_ON and fixed all callers of unregister_blkdev().  Now we can make
unregister_blkdev return void.

Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

block/genhd.c

@@ -108,13 +108,11 @@ int register_blkdev(unsigned int major, const char *name)
 
 EXPORT_SYMBOL(register_blkdev);
 
-/* todo: make void - error printk here */
-int unregister_blkdev(unsigned int major, const char *name)
+void unregister_blkdev(unsigned int major, const char *name)
 {
 	struct blk_major_name **n;
 	struct blk_major_name *p = NULL;
 	int index = major_to_index(major);
-	int ret = 0;
 
 	mutex_lock(&block_subsys_lock);
 	for (n = &major_names[index]; *n; n = &(*n)->next)
@@ -122,15 +120,12 @@ int unregister_blkdev(unsigned int major, const char *name)
 			break;
 	if (!*n || strcmp((*n)->name, name)) {
 		WARN_ON(1);
-		ret = -EINVAL;
 	} else {
 		p = *n;
 		*n = p->next;
 	}
 	mutex_unlock(&block_subsys_lock);
 	kfree(p);
-
-	return ret;
 }
 
 EXPORT_SYMBOL(unregister_blkdev);

include/linux/fs.h

@@ -1527,7 +1527,7 @@ extern void putname(const char *name);
 
 #ifdef CONFIG_BLOCK
 extern int register_blkdev(unsigned int, const char *);
-extern int unregister_blkdev(unsigned int, const char *);
+extern void unregister_blkdev(unsigned int, const char *);
 extern struct block_device *bdget(dev_t);
 extern void bd_set_size(struct block_device *, loff_t size);
 extern void bd_forget(struct inode *inode);